Now in his mid-60s, Sir John has enjoyed a stellar career over the past 40 years. After a stint as a civil engineer, the bass singer made his Royal Opera debut in Salome in 1977 and since then has become one of the opera world’s most eminent performers, known in particular for his interpretation of Wagner. In the past 34 years, he’s trodden the boards of the world’s leading opera houses – singing at Bayreuth every year between 1988 and 2004 and receiving a knighthood in 2005. Despite the acclaim he’s received he remains extremely down to earth. "I’ve done far more than I ever thought; I’m still learning stuff all the time”. It’s clear he relishes his new part in one of the operas he is most closely associated with.

In the course of his career Sir John has taken a wide range of parts: “I’ve spent the last 20 years singing the best bass parts –from Claggart in Billy Budd to King Philip from Don Carlos, not to mention all those great Wagnerian roles. I’ve also had the honour of having two great parts written for me for this house by Harrison Birtwistle – the eponymous Minotaur and The Green Knight in Gawain. They’re all great parts for a voice like mine. I never expected to do some of them as they’re bass baritone parts and never thought my voice would be high enough. Fortunately however, it seems to have worked out well. There are certain parts I haven’t done that I’d like to however – Nick Shadow in The Rake’s Progress for example.”

He has over the years, worked with an extraordinary range of artists which reads like a who's who of the operatic and classical world. His first Meistersinger at Covent Garden was in 1993, when he sang the role of Hans Sachs with Thomas Allen as Beckmesser: “Thinking about working with Tom as Beckmesser in particular brings a smile to my face. He’s a very human performer and extremely creative, as well as being rather funny when he wants to be. We’ve had some great times.”

Conductors too have also left their mark on Sir John: “Conducting is a very mysterious business. I hugely enjoyed working with Bernard Haitink – he conducted Meistersinger so beautifully. In rehearsal, he doesn’t say much but everybody who is there is on the edge of their seats waiting to make great music - he’s got this magnetism.”

Over the course of his career, the singer has noticed a change in the approach in the approach of conductors: “I’ve worked with the likes of Von Karajan, Solti and Muti. The old school – Von Karajan and Solti – had the old dictatorial, tyrannical approach. It was very impressive and as a singer you did absolutely what they wanted. They didn’t give you much leeway or freedom. These days things are different. Antonio Pappano is conducting this revival and he is a joy to work with, he keeps a perpetual, lively pulse from start to finish of this long piece. No dictator, yet very demanding.

“I was taught a great deal about discipline in particular by the German director Harry Kupfer who I worked with on The Ring at Bayreuth in 1988. He taught me about stillness and intensity – a combination of the two. You don’t need to move and if you do it may be a very explosive movement, but stillness doesn’t mean deadness, it means even more effort mentally. It took me time to learn that.”

“Give audiences pleasure and express emotion. If you’ll be famous, you’ll be famous,” he muses when asked what his advice to younger singers would be, “concentrate on giving excellent performances”. Sir John’s work ethic and belief in the importance of art seemingly reflects those held by the Meistersingers in the opera.

This month’s revival of Graham Vick’s acclaimed production sees Sir John Tomlinson shift roles from Hans Sachs, the selfless cobbler at the centre of the opera to the character of Pogner. During this run Wolfgang Koch will play Sachs, and Sir John speaks with approval of “the natural turning of the pages of the generations. Wolfgang is 20 years younger than me. It’s right that that should happen.”

Sir John sees both roles as key in the story: “Pogner gets the story off the ground by the grandiose act of giving his daughter as the prize for the singing contest on Midsummer’s Day. He spreads goodness and believes in art, in music and the cause of the Meistersingers. On the other hand, Sachs takes a back seat at the beginning – he comes to the fore later. He’s a classic Wagnerian character in that he relinquishes his love of the daughter because he sees that the daughter and Walther, the young knight, are in love. He gives up his own entitlement to her. There’s nothing he’d like more than to marry Eva and have 20 children with her but he sees her and Walther’s love and makes it work out for them, in spite of all the complexities”.

The role is a mammoth undertaking for any singer: “Sachs is on stage for four hours and sings for two and half of those. I think it’s the longest operatic role ever written but probably due to the role’s very personable and human nature, it doesn’t give the impression of overwhelming length.” As such, preparation is key. “It’s a bit like running a marathon,” Sir John says, “It’s a very physically demanding role as a lot of the power comes from the diaphragmatic muscles. They’re important in supporting the sound over a long period of time, which is why a lot of Wagnerians have got that chunky figure. Even a lot of singers who look slim are often very muscular.”

So what is it about Richard Wagner that has inspired Sir John to devote a sizeable part of his career to the composer’s work? “One of Wagner’s great philosophies was that of Gesamtkunstwerk – a total work of art. He wanted a continual dramatic flow and hence the combination of acting and singing. Orchestrally too there’s a lot of fantastic thematic material - leitmotifs. What’s great is that these themes develop along with the characters. The music tells these dramatic stories at deeper levels than often the characters are aware of. It’s very clever and extremely rich.

“For some people there are a lot of political overtones and baggage with Wagner’s work in particular Meistersinger – it was after all Hitler’s favourite piece, I don’t deal with that though, I deal with the piece itself. As a singer that’s what you’re focussed on: the words, the text, the notes, the relationship between the characters. For me, if you play the piece in 1542 I don’t regard the piece as being remotely fascist. There is a hint of nationalism but no more than many operas – Billy Budd for example. Rule Britannia contains a nationalist idea but when we all sing along on the last night of the Proms, we don’t take it very seriously,” then as if to leave no doubt, he says emphatically, “There’s nothing about Meistersinger that upsets me politically or ethically. It’s a wonderful piece because it’s a very sophisticated text. There’s great drama and the music is just glorious – it’s great theatre.”